brine washings: before or after A/B & vac-distill?

[ChillyBee]

Just returned to the laboratory and have a question before I proceed much further...

Before, when the MM al/hg nitro reaction was almost complete and the goods were in the toluene, a series of washings with dH2O & brine would follow.  Now I am convinced that it is necessary to perform an A/B extraction and to then vacuum distill the toluene/MDMA.  So now I am wondering at what point this series of washes should take place? 

It would seem redundant to first do these and then perform the A/B extraction and vacuum distillation.  My guess is that these series of washings would come after the vacuum distillation and prior to drying.  But I don't know for sure so am hoping a bee with more experience can provide some advice.

Thanks again everybody...

[hCiLdOdUeDn]

If you are planning to distill after the A/B procedure then you dont need to do the washes. The washes are for lazy bees who dont want to distill.

Distilling is essential every step of the way, especially the last step. This should be a golden rule here. Its been mentioned many times before.

[ChillyBee]

So after the A/B extraction and then vacuum distillation, one can immediately dry the toluene/MDMA with magnesium sulfate.  There would be no need to perform washings before the A/B extraction.  Right?

Is it still recommended to chill the dry toluene/MDMA before the gassing starts?  I know crystals can form in the toluene at room temperature.  But for the two subsequent gassing runs, it is probably necessary to chill.  Right again?

Thanks

[hCiLdOdUeDn]

There are many routes to gassing. Some prefer gassing in acetone, some in xylene or toluene. I prefer gassing in dry toluene. You dry the toluene first, then add the MDMA freebase to the toluene. Then you can gas at room temperature for the first gassing. The second gassing, gas at room temp, then place the beaker/flask in a freezer overnight and you will have a nice second crop of crystals.

Good luck~

[ChillyBee]

I'm a little bit confused when you say 'dry the toluene first, then add the MDMA freebase to the toluene.'  So one has a batch of toluene/MDMA being vacuum-distilled and a fresh portion of toluene that is being dried with MgSO4.  When the distillation is complete, this toluene/MDMA is then added to the new toluene that has been drying. Is this what you mean?  If so, what is the reason that new (& dry) toluene must be mixed with the now distilled and cleaner MDMA/toluene?

This reminds me of the crystallization section at the end of TSII.  Strike says that the amine/toluene should be added to a bit of DCM which dissolves any impurities (and produces 'weird-looking' crystals).  But I recall some bee saying (I think Rhodium) that one should not dissolve MDMA/toluene in DCM, but it might be alright to do this for MDA/toluene. 

Sorry if this doesn't make sense and/or my memory isn't serving me right.

[ChillyBee]

I forgot about something else again.  hCiLdOdUeDn, you say 'there are many routes to gassing' which is very true. 

In the past I had bookmarked an old post by Osmium where he mentioned another way to form crystals.  (look at

Post 383107

(Osmium: "Finally someone is doing this MeNO2 prereduction.", Methods Discourse)) At the bottom of this post he states: 'I can also recommend the following crystallization procedure: dissolve freebase in IPA, gas with HCl, and then crash out the product with excess acetone. Store at -20°C for some time and filter. Save those mother liquors, still some goodies in them!'  Does any bee that has used this method have any more information?

This reminds of of what I just mentioned in the previous post about adding the toluene/MDMA to DCM, except instead it is added to IPA (which I assume to be dry and possibly chilled too).  But what might be the relative amounts?  For example, if one wanted to try this with 100mLs of toluene/MDMA, how many mLs of IPA would this be added to?  And then how many mLs of acetone should be dripped in?  (Sometimes I read the amount of acetone should be four times the amount of freebase, but don't know for sure.)

But maybe Osmium doesn't mean for the IPA (and toluene) to be dry.  If both were, the crystals would come out during the gassing and there would be no need for adding the acetone.  Is this correct?  Probably not...

[Rhodium]

Strike says (erroneously) that you can gas both MDMA and MDA in DCM, while you actually only can gas MDA in DCM, as MDMA.HCl is partly soluble in DCM, and will therefore not precipitate fully from such a solution. MDA.HCl is insoluble in DCM, so that works just fine.

[hCiLdOdUeDn]

ChillyBee,

After you have collected your freshly distilled MDMA freebase, weigh it out and add 10x its weight of dry toluene to dissolve the MDMA freebase in. Then gas.

After a reduction you should have done an A/B procedure to get rid of any ketone. That way distillation of the freebase just removes the impurities, so no MDP2P or MDP2Pol comes over, which can contaminate your product. You shouldnt distill the freebase with the toluene over together, thats bad lab technique. Carefully distill over each fraction and collect and store each fraction in its own container.